Re: general protection fault in open_fs_devices

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger  
crash:

Reported-and-tested-by:  
syzbot+909a5177749d7990ffa4@xxxxxxxxxxxxxxxxxxxxxxxxx

Tested on:

commit:         b0b8c45747a5 wip streamline uuid locking in btrfs_mount_root
git tree:        
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git/test-syzbot-fs-devices
kernel config:  https://syzkaller.appspot.com/x/.config?x=26c272eeaa8c437e
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)

Note: testing is done by a robot and is best-effort only.